Fuel supply apparatus

Abstract

A fuel injection apparatus includes a valve element provided with a flow passage allowing a fuel to flow therethrough, a valve seat which the valve element will contact with or separate from, and a casing accommodating therein the valve element and the valve seat. During valve opening in which the valve element is separated from the valve seat, the fuel flowing through the flow passage is discharged through a gap between the valve element and the valve seat. A direction in which the valve seat is placed relative to the valve element is the same as a direction of the fuel flowing in the flow passage. The fuel injection apparatus further includes a discharge-side flow passage in which the fuel to be discharged during valve opening is allowed flow. The discharge-side flow passage is formed outside an outer peripheral portion of the valve seat.

What is claimed is: 
     
       1. A fuel supply apparatus including a valve element having a through hole that provides a flow passage which allows fuel to flow therethrough, a valve seat which the valve element comes into contact with or separates from, and a casing accommodating the valve element and the valve seat,
 wherein the valve element is configured to separate from the valve seat during valve opening to allow the fuel flowing in the flow passage to be discharged through a gap between the valve element and the valve seat, 
 wherein the fuel is allowed to flow in the same direction in the flow passage as a direction in which the valve seat is arranged with respect to the valve element, 
 wherein the fuel supply apparatus further includes a discharge-side passage to allow the fuel to be discharged out during the valve opening, and 
 wherein the discharge-side passage is provided outside of a radial-outward-facing peripheral portion of the valve seat. 
 
     
     
       2. The fuel supply apparatus according to  claim 1 , wherein
 the discharge-side passage is formed over an entire circumference of the outer peripheral portion of the valve seat to allow the fuel which will be discharged during the valve opening to spread in a nearly radial fashion in the discharge-side passage. 
 
     
     
       3. The fuel supply apparatus according to  claim 1 , further including a seal member placed between the valve element and the casing. 
     
     
       4. The fuel supply apparatus according to  claim 3 , wherein
 the valve element has a nearly cylindrical shape and includes a seat sealing member on a surface of the valve element on a side where the valve seat is arranged, 
 the seat sealing member is provided with a contact portion that contacts with the valve seat during valve closing in which the valve element is held in contact with the valve seat, 
 the seal member and the contact portion are formed in an annular shape centered on a central axis of the valve element, and 
 the contact portion has a diameter equal to a diameter of the seal member. 
 
     
     
       5. The fuel supply apparatus according to  claim 3 , wherein
 the valve element has a nearly cylindrical shape and includes a seat sealing member on a surface of the valve element on a side where the valve seat is arranged, 
 the seat sealing member is provided with a contact portion that contacts with the valve seat during valve closing in which the valve element is held in contact with the valve seat, 
 the seal member and the contact portion are formed in an annular shape centered on a central axis of the valve element, and 
 the contact portion has a diameter larger than a diameter of the seal member. 
 
     
     
       6. The fuel supply apparatus according to  claim 1 , wherein
 the casing is provided with a side portion placed outside of an outer peripheral portion of the valve seat, and 
 the discharge-side passage has an outlet formed in the side portion. 
 
     
     
       7. The fuel supply apparatus according to  claim 1 , wherein
 the discharge-side passage has an outlet formed in a position forward in a discharging direction of the fuel to be discharged through a gap between the valve element and the valve seat during the valve opening. 
 
     
     
       8. The fuel supply apparatus according to  claim 1 , wherein
 the discharge-side passage extends alongside the valve seat outside of the radial-outward-facing peripheral portion of the valve seat.